Celo L2 Specification

How the Celo L2 implementation differs from the OP Stack it is built on

This document describes the differences between the Celo L2 implementation and Optimism’s OP Stack, on which it is based. Refer to the OP Stack specs for details on the unmodified OP Stack.

The L1→L2 migration changes page details the differences compared to the Celo L1 blockchain. The Celo L2 is a continuation of the L1 by using its state and providing a high level of compatibility with it.

Background

In May 2024, the Celo Community decided to move from an L1 blockchain to an L2 built on the OP Stack. The move was approved in CGP-133, which set out to improve scalability, security and interoperability with Ethereum, and it completed in March 2025 at block 31,056,500. Celo L2 kept the existing ecosystem and state while integrating with Ethereum. See About Celo L1 for what the L1 was and Our History for the timeline.

New Features

• Token duality, access native tokens via ERC20
• Fee Abstraction, pay gas with ERC20 tokens

Technical Differences

• New transaction types to support Fee Abstraction
• One new precompile to support token duality
• Changes to finality
• The MaxCodeSize for newly deployed contracts is increased from 24576 to 65536.

Deployments

• Mainnet
• Celo Sepolia testnet